Self-sealing "breakaway" fluid couplings are utilized in applications where tension forces applied to conduits will rupture the conduits, or associated fittings. Such couplings are used with agricultural equipment such as tractor-drawn farm implements having automatic releasing hitches, and breakaway couplings are often required by aircraft specifications for "crashworthy" fuel systems whereby fuel tanks are interconnected by breakaway couplings to prevent fuel loss during impact.
Crashworthy couplings may utilize frangible components for maintaining the coupling parts connected during normal use, or reusable couplings may employ spring biased locking structure released by tension forces such as disclosed in U.S. Pat. Nos. 2,860,893; 3,140,102 and 3,781,039.
It is an object of the invention to provide a breakaway or crashworthy fluid coupling which is dependable in operation and economical to manufacture and assemble.
Another object of the invention is to provide a breakaway coupling utilizing a pair of body parts each housing seal-sealing valves therein radially displaceable detents are selectively positionable within a groove and maintained therein by a retainer, the retainer directly sensing the axial forces within the conduit system associated with the coupling.
A further object of the invention is to provide a breakaway coupling having self-sealing valves incorporated within releasable body parts, the parts utilizing latching structure employing an annular axially displaceable operating member, and a conduit being directly attached to the operating member whereby tension forces within the conduit are directly imposed upon the operating member.
In the practice of the invention, the coupling consists of a pair of body parts each having a passage defining a flow path and a spring biased self-sealing valve is located within each flow path. The body parts include latching structure for maintaining the parts in a coupled relationship, and when coupled, the self-sealing valves operatively engage and are axially displaced to an open condition permitting fluid flow through the coupling.
The latching structure includes radially movable detents in the form of balls and an annular retainer for radially positioning the ball detents. The retainer comprises a tubular latch operating member and one of the flexible conduits associated with the coupling is sealingly affixed directly to the operating member.
A spring biases the operating member toward the detent retaining position, yet sufficient axial force imposed upon the conduit attached to the operating member displaces the operating member to permit release of the detents, and disengagement of the coupling parts.
As the operating member is sealed with respect to its associated body part, the coupling is fluid tight, and the direct association of the conduit with the latch operating member produces a concise assembly of low cost and dependable operation.